LETTER: Get real on ATAR scales

By
GLEN COULTON

Dec. 26, 2012, 9 p.m.

CONFUSION over why seemingly high higher school certificate (HSC) marks don’t always lead to high Australian Tertiary Admission Ranks (ATARs) will not lessen while newspapers and others continue to fertilise the misconception that some subjects are scaled up and some scaled down.

CONFUSION over why seemingly high higher school certificate (HSC) marks don’t always lead to high Australian Tertiary Admission Ranks (ATARs) will not lessen while newspapers and others continue to fertilise the misconception that some subjects are scaled up and some scaled down.

Subjects are not scaled – candidatures are.

If one candidate doing a hard subject and another doing an easier subject both score near the middle, their marks will be about the same, reflecting the fact that within those candidatures, each was about average.

But if one subject attracted mainly outstanding students and the other mainly average students, the ATAR will place a higher value on the mark of the student who was average in the outstanding group rather than on the mark of the student who was average in an ordinary group.

When that student’s mark for that subject is scaled up, it has nothing to do with whether the subject was hard or easy, academic or vocational; it is entirely to do with the ability of the other students who happened to take it.

Of course, the outstanding students usually happen to take the so-called hard subjects, allowing the unthinking (and the misled) to assume that it is the importance or difficulty of a subject that determines how its marks are scaled.

Because it is the ability of the students presenting it, not its perceived worth, that determines how the ATAR values the marks obtained in each subject, it would help greatly if everyone stopped talking about ‘‘high scaling subjects’’ and ‘‘low scaling subjects’’. It would help further if everyone stopped implying that candidates can ‘‘score’’ an ATAR like they can an examination mark.

An ATAR doesn’t measure how much you knew in a subject; it records how many other candidates you beat overall.